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

Beyond the annotations (openWorldHint, non-idempotent, non-destructive), it discloses the exact preflight checks (listen_port, making the project public, URL answering), the two possible statuses returned (live vs publishing), and the failure semantics (refusal with no state change). This is exactly the behavioral context annotations cannot carry.

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?

Front-loads the verb, the resource, and the resulting URL before any caveats, and every clause carries information. It is dense and somewhat run-on with stacked colons and parentheticals, costing a bit of scannability.

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?

Covers preconditions, side effects, failure mode, and workflow ordering for a non-idempotent, open-world mutation. Even though an output schema exists, the description's status explanation reinforces what success looks like without redundant detail.

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%, so both parameters are already documented at baseline. The line 'Pass project_id; a server with exactly one project deploys that one without it' restates what the schema's project_id description already says, adding emphasis but no new semantics.

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 (deploy) and resource (a project to its live public URL), and concretely describes the outcome URL pattern. It explicitly positions itself against start_app, start_build, and prompt, so an agent can distinguish it from siblings without opening schemas.

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?

Gives explicit when-to-use (last step in putting a site online), when-it-won't-work (nothing listening on listen_port → refuses and leaves project unchanged), and named alternatives plus ordering (start_app after write_file, or start_build/prompt). Nothing is left to inference.

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