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

Beyond the read-only/idempotent annotations, it discloses key behavioral traits: each row reports same/different/partial/not comparable/incomplete, missing data is never fabricated, and peptides are never ranked. This is exactly the kind of non-obvious behavior an agent needs.

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-loads the purpose and scope, then adds the behavioral caveats. The middle sentence is dense with enumerations but each element earns its place; no filler.

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?

An output schema exists, so return values needn't be explained, and the annotations cover the safety profile. The description still adds the comparison semantics and no-ranking guarantee, making it complete for this read-only comparison tool.

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% and both parameters are fully documented there (ids/names/aliases, and the dimensions enum). The description's mention of structured fields loosely maps to dimensions but adds no syntax beyond the schema, so 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 (compare), resource (peptides), and scope (2-3 peptides side-by-side), and enumerates the exact profile fields compared. This clearly distinguishes it from single-entity siblings like get_peptide_details and search_peptides.

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 implies usage ('Suitable for tables', 'No dosing information' excludes out-of-scope intent) but never explicitly names when to choose this over get_peptide_details or search_peptides. Usage is inferable but no alternative is called out by name.

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