One function's score across runs

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

Beyond the readOnly/idempotent annotations, the description discloses meaningful behaviors: results are ordered oldest first, history spawns git log -L capped at 10 commits, tests is null unless contexts were recorded, and name resolution uses the newest run scoring path with substring fan-out. This adds real behavioral context the annotations alone do not provide.

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 front-loaded with the core return value and usage, and every sentence contributes useful information. It is somewhat dense, especially in the trailing clauses about history/tests/name/repo, but remains well-structured and not padded.

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?

With an output schema present, the return shape is already covered. The description completes the picture by specifying ordering, optional-parameter behavior, name resolution rules, repo scope, and the sibling alternative. An agent has enough context to invoke this tool correctly without further inference.

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?

Although schema coverage is 100%, the description adds important semantic details beyond the parameter descriptions: history's git log cap, tests' null behavior, name's newest-run resolution and substring fan-out, and repo's flexibility to any directory under the checkout. This materially helps an agent choose and format parameter values correctly.

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 states a specific action and resource: it returns one function's ccn, coverage, crap, flag, and ratchet mark across runs, oldest first. This clearly distinguishes the tool from siblings like get_function_brief and get_trend by focusing on per-run history for a single function.

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 explicitly says to use this tool to tell improving from decaying or regrown functions, and to use get_function_brief instead when starting an edit. This gives the agent both a positive use case and a concrete alternative, satisfying the when/when-not guidance requirement.

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