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

Annotations already declare readOnlyHint=true and idempotentHint=true, and the description adds non-contradicting richness: it discloses that report bodies can be 10–100KB, that over-budget records return a section outline with byte sizes, and that 'Nothing is truncated on either path.' This tells the agent exactly what to expect for large payloads without having to discover it. The explanation that the call is self-contained ('record is re-fetched and sliced') adds operational transparency beyond the schema.

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 dense but every sentence earns its place. The first sentence establishes purpose, the second provides usage context, and the remaining sentences explain the size-handling behavior and self-containment. It is front-loaded with the action, flows logically, and contains no redundant phrasing.

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?

Given that the tool has only two parameters, an existing output schema, and safety annotations, the description covers all necessary operational details: how to obtain the ID, when to use sections, what happens for large reports, and that no truncation occurs. It even notes that identity metadata is always included. An agent can correctly invoke this tool with no ambiguity.

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%, so the baseline is 3, but the description adds meaning beyond field definitions. It clarifies that 'sections' values must match exactly as the outline spelled them, and explains the behavior of omitting sections (whole record vs. outline for over-budget records). This transforms a vague array parameter into a well-understood control for response size management.

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 'Fetch a single ReliefWeb report by its numeric ID with full body text, file attachments, and all metadata,' which is a specific verb plus resource and scope. It differentiates from siblings by explicitly instructing 'Use after reliefweb_search_reports to retrieve document content,' making it clear this is the report-specific retrieval tool versus other resource fetchers.

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 description provides explicit when-to-use guidance: 'Use after reliefweb_search_reports' and explains why body is excluded from search results. It also details the conditional behavior for large reports (over response budget → outline → re-call with sections), giving the agent a concrete decision path for handling oversized responses.

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