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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the description is not needed for the safety profile. It nonetheless contributes beyond them: the authentication token and its creation path, the plan eligibility gate, per-account data scoping, the no-inference rule from product name, and the degraded answer when Section 8 can't be read.

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 what is returned and the source location, then prerequisites and exclusions, which is the right order. A few clauses are arguably redundant with annotations, notably the closing 'Read-only; reads only that account's data', which repeats readOnlyHint and the earlier inventory scoping.

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?

No output schema exists, and the description covers the return shape: the lines copied as printed plus a link to the sheet, along with the degraded answer text. For a one-parameter read tool with full annotation coverage, nothing the agent needs to invoke or interpret it correctly is 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 100% and the single parameter already carries an example, so the baseline is 3. The description adds real meaning by constraining the value to a name in the caller's own SDSentry inventory and warning that nothing is inferred from the product name, which tells the agent exact-match entry matters.

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?

Opens with a specific verb and resource: returns the PPE and exposure-control lines from Section 8 of the SDS on file, enumerating the sub-sections (eye/face, hand, skin and body, respiratory, engineering controls, hygiene). It also scopes itself to the caller's own inventory and names the sibling (find_safety_data_sheet) that handles everything else, so an agent can pick between them without opening a 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?

Gives explicit routing ('Products you do not hold are not looked up here (use find_safety_data_sheet)') plus the prerequisite conditions: a personal SDSentry access token created by the account owner, and a free-trial or paid plan. It even states the fallback behavior when Section 8 is unreadable, which is when-not guidance in practice.

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