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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds the behavioral context that the tool reveals build outcomes and current-live state, which is beyond what annotations alone convey. It doesn't describe pagination or response format, but with output schema present, this is acceptable.

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, zero waste. Opens with the core function, then usage context and an alternative. Every sentence earns its place with distinct information—purpose, downstream consumers, and exclusion.

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 simple list tool with 2 params (1 required), full schema coverage, annotations, and an output schema present, the description is complete. It covers purpose, usage when to reach for it, and ties to related tools. Nothing essential is missing for agent selection and invocation.

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% per context signals, so both parameters are documented in the schema. The description adds practical value on the 'project' parameter through a sibling reference (my_projects for slug lookup) that isn't in the schema, enriching agent guidance. Baseline 3 plus this added semantic context justifies a 4.

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 clearly states what it does: lists recent project builds, their outcomes, and which one is currently live. It distinguishes itself well from siblings like site_status and explicitly names rollback and diagnose_deploy as downstream purposes. The verb+resource+scope is specific and clear.

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 gives explicit when-to-use guidance: pick a target for rollback or diagnose_deploy. It also explicitly excludes a case—'what's wrong with the site right now'—and points to site_status as the cheaper alternative. This is exemplary usage guidance with named alternatives and exclusions.

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