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

Goes well beyond the annotations by disclosing that the read is audited against the calling token and visible to the secret's owner, plus a handling constraint (do not copy into comments, descriptions, merge requests or logs). This is exactly the kind of consequence an agent cannot infer from readOnlyHint/destructiveHint. However, it does not say anything about failure modes (e.g. permission denied, missing id, whether reveal is rate-limited or requires a second confirmation), so the disclosure, while valuable, is not complete.

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?

Four sentences, each doing distinct work: purpose, the audit consequence, the timing rule, and the handling rule. The purpose is front-loaded and 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?

For a one-parameter, no-output-schema tool, the definition covers purpose, prerequisite, side effects and post-call handling, which is close to everything an agent needs. It stops short of describing the return shape or error behavior, but with no output schema and annotations already declaring the non-destructive profile, that omission is minor.

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?

Only one parameter and schema description coverage is 100%, so the schema already explains that id is a credential id from list_credentials. The description repeats that provenance ('by the id from list_credentials') but adds no format, range or edge-case detail beyond the schema. Baseline 3 for a fully-described single param.

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 ('Read one credential's value') and pins the source of the identifier to list_credentials, which cleanly separates it from create_credential, update_credential and delete_credential in the sibling set. An agent can identify this as the single read-one-secret tool without opening the 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 states when to call it ('when you are about to use the value, not to have it on hand'), which is both a positive condition and an exclusion. It also names list_credentials as the prerequisite for obtaining the id, so the call sequence is fully determined.

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