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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real behavior the annotations don't: the default response shape when no section is supplied (summary + section list) and the fact that content includes verbatim study quotes and numbered sources. No pagination or size limits are disclosed.

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?

Two sentences, front-loaded with the core action and return content, then the parameter-mode distinction. Nothing is redundant with the schema or annotations.

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 two-parameter read tool with full schema coverage and rich annotations, the description supplies everything an agent needs: what the payload contains, both calling modes, and how to discover valid section ids. No output schema exists, and the description adequately characterizes return contents instead.

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 goes beyond the schema by naming concrete section values ('human record', 'regulatory status', 'safety', 'mechanism') and explaining that the section list comes from a section-less call — a discovery mechanism the schema only hints at.

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: get the evidence on ONE peptide from a research dossier, including verbatim quotes and numbered sources. The singular 'one peptide' plus 'research dossier' distinguishes it implicitly from list_peptides and compare_peptides, which operate on sets.

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 describes the two calling modes: omit section to get the summary plus section list, or pass a section to read that part in full. It does not, however, route the agent toward or away from the sibling tools (list_peptides for discovery, compare_peptides for multi-peptide work).

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