Convergence Score

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With only readOnlyHint: false in annotations, the description carries the burden of explaining side effects. It adds meaningful behavioral context: the operation is deterministic, involves no new analysis, and 'emits a recomputable receipt' as durable evidence. It also notes the requirement for a base git ref, giving the agent a clear picture of what executing this tool entails.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is four sentences and front-loads the core purpose, then explains sub-scores, composition, receipt behavior, and requirement. Each sentence carries substantive information without fluff, though the sub-score explanation could be considered verbose for a quick scan. Overall it is efficient and well-structured.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 6-parameter tool with no output schema, the description covers the key aspects: what the result measures (score with sub-scores), that it emits a receipt, and the prerequisite base ref. It does not describe error conditions or how to interpret edge cases, but the core information an agent needs to call it correctly is present.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3. The description restates the purpose of the 'base' parameter ('Requires a base git ref to diff against') but adds no extra meaning beyond the schema's own descriptions. It does frame the 'query' parameter as the 'stated task / intent,' which slightly reinforces the schema, but no parameters gain new depth from the main description.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb and resource: 'Score convergence' between a stated task and the actual git diff. It goes beyond a simple label by defining the deterministic 0–100 measure and listing sub-scores (Coverage, Scope, Risk alignment), which clearly distinguishes it from siblings. The reference to being 'Composed from the change_impact diff comparison' further separates it from the raw change_impact tool.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage context by stating it requires a base git ref and is composed from change_impact, but it never explicitly says when to choose this tool over alternatives like review_gate or change_impact. There is no 'use this when...' or 'instead of...' guidance, leaving the agent to infer the appropriate scenario.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.