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

Annotations already signal a write operation (readOnlyHint:false, idempotentHint:false). The description adds useful context by declaring the required auth scope, the exact endpoint, and warning against inventing alternate paths. There is no contradiction with the annotations.

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?

The description is compact and front-loaded, with each sentence earning its place: format, scope, endpoint, and API constraints. The warning 'Do not invent other paths' is concise and actionable.

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 three-parameter upload with full schema coverage, the description supplies the necessary API identity, auth scope, and endpoint. It does not describe response or error behavior, but with no output schema and a straightforward upload this is a minor gap; the main missing piece is explicit sibling differentiation.

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 the schema already documents all three parameters. The description only reinforces the certificate/key concept and does not add new meaning about cert_type, cert_data, or x_app_id beyond what the schema states.

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 opens with a direct statement: 'Uploads a single PEM-encoded certificate or key.' This gives a specific verb and resource, and the PEM format distinguishes it from the sibling uploadP12Certificate. Mapping to POST /manage-certs further anchors the operation.

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 provides operational context such as scope certs:manage, the exact OpenAPI operation, and the note about the same API/rate limits. However, it never explicitly states when to use this tool over uploadP12Certificate or other upload tools, so the usage guidance is clear but lacks explicit alternatives or exclusions.

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