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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered; the description adds the substantive behavior an agent couldn't infer — that results are "editorially verified," carry a last-verified date, and link to a full profile. The last-verified date is a meaningful freshness caveat that no annotation conveys.

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 compact sentences: trigger, return description, then exclusions. Zero filler and the highest-value information (what it does and when it applies) is 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?

For an 8-parameter, all-optional search tool with no output schema, the description covers the return shape and the freshness signal that matter most. Remaining gaps (result ordering, whether offset pagination exists beyond limit) are minor and partly offset by the 75% schema coverage.

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 75% and the schema itself carries rich per-parameter guidance (e.g. the prep_specialist vs full_3pl explanation, the 'do not infer state from user location' warning). The description's filter list largely restates what the schema already documents, and it says nothing about limit or accepting_new_clients_only.

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 set and resource ("find, compare, or filter Amazon FBA prep centers") and enumerates the filterable dimensions, so the agent knows exactly what the tool returns. It does not name the sibling tools get_prep_center or get_directory_summary, so the boundary with those is left implicit.

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?

Gives an explicit triggering condition ("when the user wants to find, compare, or filter...") and three concrete exclusions: FBA policy questions, fee calculations, and Amazon fulfillment centers. It stops short of naming the alternative tool to use for a single center's details, which would have made routing unambiguous.

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