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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds real behavioral detail beyond that: a hard cap of 'up to 50 pronunciation rules' in the result and lookup via either project id or vanity id, which prepares the caller for truncation.

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?

Three sentences with the usage trigger front-loaded, then the return payload, then the exclusion. Efficient overall, though the trailing exclusion sentence is vague enough that it spends words without fully earning them.

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, return values need not be spelled out, yet the description usefully previews the payload and the 50-rule cap. Nothing an agent needs to invoke it correctly is missing; only the unclear exclusion clause keeps it from being fully self-explanatory.

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 coverage is 100% and the single parameter already documents 'Project id or its stable public vanity id'. The description repeats that same fact ('looked up by project id or vanity id') without adding format, constraint, or edge-case guidance, so this is the baseline 3 case.

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 a specific verb+resource ('get' a single 'project's settings') and enumerates the returned content (name, domain, locales, voice settings, pronunciation rules), so an agent knows exactly what it produces. It does not explicitly distinguish itself from list_projects or show_project_overview by name, leaving the sibling boundary to inference.

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?

It states when to reach for it ('when someone asks about one project's languages, default voice, narration speed or pronunciation rules') and includes an exclusion clause ('Not for finding languages or devices that lack videos'). The exclusion is cryptic and references no actual sibling tool, so the when-not guidance is weaker than it looks.

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