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

Goes well beyond the annotations by explaining that grades are never recalculated ('every grade comes from a record already signed') and that output separates covered files from uncovered ones with reasons. The destructiveHint/readOnly annotations already signal mutation risk, and the description adds the non-re-grading boundary, so there is no contradiction; it just doesn't elaborate what destructive side effects, if any, occur beyond issuing the certificate.

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?

Two dense sentences front-load the core action and scope, then the constraints. Every clause earns its place—there is no filler, trademark, or redundant restatement of the tool name.

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?

Description covers purpose, scope, active-certification precondition, cost-based exclusion, and expected output components. Given the annotations and full parameter schema, an agent has enough to invoke correctly, though the actual return shape and format of the issued certificate aren't stated since there is no output schema.

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?

Input schema covers both parameters thoroughly (client_id from list_certifications, title not part of the signature). The description adds only the alias that a client is a folder/organisation, so its contribution over the schema is minor; baseline 3 is appropriate.

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 the exact action and target: 'issue a signed TomeVault certificate for one organisation (a client folder).' The next clauses add distinctive scope rules (matching records covered, others listed with reasons, no re-grading) that separate it from listing/verification siblings such as list_certifications and verify_attestation.

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?

Provides an explicit precondition and exclusion: it only works when the client's certification is already active and cannot be used to activate one because activation costs money. This tells an agent when not to call, though it doesn't name an alternative activation tool; the schema's client_id reference to list_certifications is the only pointer for setup.

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