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

Annotations cover the safety profile (readOnlyHint=true), so the description carries a lighter burden. It adds useful behavioral context by enumerating the returned facts (last tested, branch, test file), which is valuable given there is no output schema. It does not mention permissions or empty-coverage behavior, keeping it short of a 5.

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 listing the verb, scope, and returned facts with zero filler. Every clause earns its place.

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 usefully names the key return fields, and the readOnly annotation covers the safety question. Only minor gaps remain (pagination/empty-result behavior), which are low impact for a read-only lookup.

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 both parameters (project slug, requirementKey) are already fully documented in the schema, including the hint to find the slug with list-projects. The description adds no syntax or format detail beyond what the schema provides, so the baseline 3 applies.

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?

States a specific verb (Get) and resource (test coverage for a requirement) and enumerates what it returns (last tested date, branch, test file). It is clearly distinct from get-requirement (metadata) and get-project-coverage-summary (aggregate), though it never names those siblings explicitly.

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 phrase 'for a specific requirement' implies the scoped use case, but there is no explicit when-to-use, when-not-to-use, or routing to alternatives such as get-project-coverage-summary for aggregate coverage or get-requirement for requirement details. Usage must be inferred.

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