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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile needs no repeating. The description adds genuine behavioral context beyond that: what comes back (short educational profiles with evidence level and canonical URL) and a content limitation (no dosing data). It stops short of describing pagination behavior, but offset/limit are self-documenting in 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?

Three tightly packed sentences: scope and searchable fields first, return contents second, sibling routing and exclusion last. No filler, no restatement of the tool name, and the most decision-relevant facts are front-loaded.

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 need no elaboration, and the description still summarizes them usefully. With all five parameters documented in the schema and the alternative tool named, an agent has everything required to select and invoke this tool correctly.

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%, including examples for query and a pointer to get_peptide_categories for the category enum, so the schema does the heavy lifting. The description restates the same field semantics (name/synonym/alias, fuzzy, category, research area) without adding format or syntax detail beyond it, 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 (search) over a named resource (Peptide Library research database) with the searchable fields (name, synonym, alias, fuzzy matching) and the optional filters. It is immediately distinguishable from get_peptide_details, which it explicitly names as the deep-dive sibling.

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?

Routes the agent to the correct alternative with an explicit condition: "Use get_peptide_details for the full profile." It also sets a scope exclusion ("No dosing information"), so an agent knows when this tool will not satisfy a request.

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