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

With no annotations, the description carries the full burden and does well: it discloses that this only initiates a staging deploy (not production), that the response is an upload_id tied to a presigned PUT, and that a token may be conditionally required by an environment flag. Gaps remain around failure behavior, presigned URL expiry, and whether re-invoking creates a duplicate deploy.

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-loaded with the action and result, then the alternative, prerequisite, and follow-up in order of need. The final clause ('PUT the zip then commit_deploy_upload') is clipped enough to feel telegraphic, but no sentence is 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?

There is no output schema, so the description correctly names the return value (upload_id) and the full upload-then-commit flow. For a mutating two-step tool with zero annotations, this is nearly complete; only error/retry semantics are missing.

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 already 75%, and the description adds sequencing meaning the schema cannot: deploy_ack_token comes from get_deployment_rules and must be reused for commit_deploy_upload. site_id, size_bytes, and sha256_hex are left to the schema, which documents them adequately.

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 and resource ('Start a staging deploy') plus the concrete artifact produced ('request presigned PUT URL for the zip'). The staging qualifier immediately distinguishes it from promote_staging_to_prod, so an agent can tell the two apart without opening either schema.

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?

Explicitly routes to the alternative ('Use promote_staging_to_prod to go live on production') and names the prerequisite path ('Requires deploy_ack_token from get_deployment_rules when MCP_ENFORCE_DEPLOY_ACK is on'). It also states the follow-on call ('Pass the same token to commit_deploy_upload'), giving a full when-to-use and what-next picture.

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