Home / Token cost / SpecLock - AI Constraint Engine

The SpecLock - AI Constraint Engine MCP server costs 2,048 tokens before the first call.

Connect SpecLock - AI Constraint Engine and its 44 tool definitions are loaded into the model's context on every request — 1.0% of a 200k window spent before your agent does anything.

QUICK ANSWER The SpecLock - AI Constraint Engine MCP server's tool definitions consume 2,048 tokens — around the median MCP server (1,905 tokens). A scoped grant exposing only the tools you use cuts that roughly in proportion.

MEASURED FROM SCHEMAS 44 tools · 2,048 tokens · 1.0% of 200k · 0.2% of 1M Method →

What that buys before your agent starts working.

Tool definitions are overhead: they occupy context on every request and compete with your code, documents and conversation history for the same window.

200K WINDOW 1.0%
1M WINDOW 0.2%

Corpus context: SpecLock - AI Constraint Engine ranks #1555 of 3,213 measured MCP servers by definition cost. The median is 1,905 tokens, p90 is 7,952, and the heaviest (Fusionauth) is 183,337 — 92% of a 200k window on its own.

Where the 2,048 tokens go.

Each row is one tool definition as a tools/list entry — name, description and input schema — counted with o200k_base. Average: 47 tokens per tool.

ToolCategoryTokens% of server
speclock_add_typed_lock Write 88 4.3%
speclock_add_lock Write 77 3.8%
speclock_add_decision Write 73 3.6%
speclock_set_enforcement Write 70 3.4%
speclock_override_lock Write 65 3.2%
speclock_set_deploy_facts Write 63 3.1%
speclock_session_briefing Execute 62 3.0%
speclock_get_events Read 61 3.0%
speclock_review_patch Write 57 2.8%
speclock_compile_spec Execute 56 2.7%
speclock_log_change Write 55 2.7%
speclock_review_patch_diff Write 55 2.7%
speclock_check_conflict Read 54 2.6%
speclock_export_compliance Write 52 2.5%
speclock_apply_template Write 51 2.5%
speclock_policy_evaluate Write 50 2.4%
speclock_add_note Write 49 2.4%
speclock_get_context Read 48 2.3%
speclock_get_changes Read 47 2.3%
speclock_guard_file Write 46 2.2%
speclock_policy_manage Write 46 2.2%
speclock_remove_lock Destructive 44 2.1%
speclock_parse_diff Execute 44 2.1%
speclock_telemetry Write 44 2.1%
speclock_update_threshold Write 44 2.1%
speclock_session_summary Write 41 2.0%
speclock_blast_radius Write 40 2.0%
speclock_checkpoint Write 40 2.0%
speclock_build_graph Execute 38 1.9%
speclock_check_typed Read 38 1.9%
speclock_set_goal Write 38 1.9%
speclock_map_locks Write 35 1.7%
speclock_semantic_audit Write 35 1.7%
speclock_list_typed_locks Read 33 1.6%
speclock_verify_audit Read 33 1.6%
speclock_suggest_locks Write 33 1.6%
speclock_override_history Read 32 1.6%
speclock_report Write 32 1.6%
speclock_auto_guard Write 31 1.5%
speclock_health Write 31 1.5%
speclock_detect_drift Read 30 1.5%
speclock_init Write 30 1.5%
speclock_audit Write 29 1.4%
speclock_repo_status Read 28 1.4%

Most agents use a handful of these tools. They pay for all 44.

A PolicyLayer grant exposes only the tools you allow — ungranted definitions are filtered out of the tool list, so they never enter the context window. Estimates below assume typical-weight tools (47 tokens each).

Grant scopeDefinition costReduction
All 44 tools (no gateway) 2,048 tokens
3 granted tools ~140 tokens −93%
5 granted tools ~233 tokens −89%
10 granted tools ~465 tokens −77%

SpecLock - AI Constraint Engine token-cost questions.

How many tokens does the SpecLock - AI Constraint Engine MCP server use?+

Its 44 tool definitions total 2,048 tokens — 1.0% of a 200k context window — measured with tiktoken o200k_base over the serialised tools/list payload. Exact counts vary slightly by client and model.

Why does SpecLock - AI Constraint Engine consume tokens before I send a message?+

MCP clients load every connected server's tool definitions — name, description, and input schema — into the model's context so it knows what it can call. That payload is charged against your context window on every request, whether or not a tool is used.

How do I reduce SpecLock - AI Constraint Engine's token usage?+

Expose fewer tools. A PolicyLayer grant scopes SpecLock - AI Constraint Engine to only the tools you allow — ungranted definitions are filtered out of the tool list, so they never enter the context window. A grant of 3 typical tools costs roughly 140 tokens, a 93% reduction.

Does deferred tool loading fix this?+

Partially, in some clients. Claude Code defers MCP tool schemas behind a tool-search step by default, and VS Code has experimental grouping — but you still pay tokens per search and reload, and Cursor, Windsurf and Gemini CLI load definitions upfront. Reducing the exposed tool set cuts the cost in every client.

How these numbers were measured.

01
Serialisation

Each tool is serialised as a tools/list entry — name, description, input schema — from the schemas in the PolicyLayer scan database. Clients differ slightly in framing, so treat counts as close estimates.

02
Tokeniser

tiktoken o200k_base (GPT-4o/o-series). Anthropic's current tokeniser isn't published, so Claude's exact counts will differ; for English text and JSON schemas the totals are close enough to treat these as estimates.

03
Deferred loading

Some clients now defer schema loading (Claude Code's tool search; VS Code experimental grouping). You still pay per search and reload — and Cursor, Windsurf and Gemini CLI load everything upfront.

Computed 07-06-2026 from the PolicyLayer scan database over all 44 catalogued SpecLock - AI Constraint Engine tools. Counts refresh with every site build.

Expose only the tools you use — the rest never enter your context.

A PolicyLayer grant scopes SpecLock - AI Constraint Engine to the tools you actually allow. Ungranted definitions never load, and every call that does run is checked against policy first.

Free to start. No card required.

4,600+ MCP servers and 31,000+ tools scanned and risk-classified.

// GET IN TOUCH

Have a question or want to learn more? Send us a message.

Message sent.

We'll get back to you soon.