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

readOnlyHint=true already covers the safety profile, so the bar is lower; the description goes further by enumerating what the statement contains (generated filter, per-reservation financials, grand totals, expenses, owner/PM details), which is valuable given there is no output schema. It omits pagination, auth, or rate-limit notes, but the return-content disclosure is substantive.

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?

A single front-loaded sentence followed by the raw endpoint reference. No filler; the returned-data enumeration is the meat and earns its place.

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 single-resource read with one fully documented parameter and a readOnly annotation, the description supplies the missing return-content detail the absent output schema would otherwise have to carry. Nothing needed to call 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?

One parameter at 100% schema coverage, so the schema already documents ownerStatementId. The description adds only that the statement is fetched by that id, contributing no format or constraint detail beyond the schema. Baseline 3 applies.

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 ('Fetch one'), the resource ('owner statement'), and scope ('one') that cleanly separates it from the list_owner_statements sibling. An agent can identify the operation 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?

The singular 'one' plus the required id imply a by-ID retrieval distinct from listing, but there is no explicit when-to-use, prerequisite, or exclusion guidance. Usage is only inferred from context and sibling names.

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