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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, covering the safety profile. The description adds meaningful behavioral detail: the case-insensitive prefix match for section headings, which is not in the schema. It does not discuss error behavior or return format, but these are less critical given the simple read operation.

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 three sentences and front-loads the core action ('Return one document in full, or just one of its sections'). The list of ids is redundant with the schema enum, but it's not verbose. The section guidance is concise and useful. No wasted words.

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 simple read-only tool with no output schema, the description covers the primary use case and the optional section behavior. Combined with annotations (safety) and full schema coverage, nothing essential is missing. Minor gaps like error handling or return format are acceptable for such a straightforward operation.

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 description coverage is 100%, so both parameters are already documented. The description adds value by listing all valid id values (also in schema) and, more importantly, specifying the prefix-match behavior for section, which is not apparent from the schema alone. This goes beyond a baseline 3.

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 states a clear verb ('Return') and resource ('one document' or 'sections'), with a concrete list of valid ids. It distinguishes itself from siblings (list, search, examples) by focusing on reading a single document, making the purpose unambiguous.

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 usage context for the section parameter ('when the whole document is more than you need'), but does not explicitly contrast with siblings like list_docs, search_docs, or get_examples. It implies this is for reading a specific doc, but no exclusions or alternative conditions are given.

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