test_plan

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

Annotations already declare readOnlyHint/idempotentHint/non-destructive, so the safety profile is covered. The description adds the meaningful guarantee that project code is never executed during detection, which resolves a plausible confusion with run_tests that annotations alone do not address.

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?

A single front-loaded sentence that states what is detected, what is reported, and the key behavioral boundary, with no filler.

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 no output schema, the description carries the burden of describing the result, and it does say it reports per-toolchain local availability. It omits any detail on report structure or failure modes, a minor gap for a simple read-only tool.

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?

There is one parameter (repo_path) with 0% schema description coverage, and the description says nothing about it. The name is largely self-explanatory, but the description does not compensate for the coverage gap with path format or scope details.

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 gives specific verbs (detect, report) and resources ('allow-listed test runners', 'required toolchain'), so an agent knows this is a capability-detection tool rather than an execution tool. It stops short of naming the sibling it contrasts with (run_tests), so it is clear but not fully differentiated.

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 clause 'without executing project code' strongly implies the counterpart tool (run_tests) and implies when to prefer this one, but it never explicitly says 'use this instead of run_tests to check availability first' or states any precondition.

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