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

Annotations already establish read-only, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuinely useful operational context beyond that: no filter returns every site, an unrecognised region/country is surfaced in a note rather than an error, and an empty list means no published match — which prevents the agent from misreading a filtered miss as a failure.

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?

Four sentences, each earning its place: purpose+scope, return fields, usage examples, sibling routing, and the empty-result edge case. The scoping and routing information is front-loaded rather than buried.

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?

With no output schema, the description compensates by listing the returned fields (slug, name, city, country, region, certifications, URL). Combined with the empty-list semantics and sibling routing, an agent has everything needed to select and call 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% and each parameter already documents its own accepted values, synonyms ('APAC', 'EMEA', 'LATAM') and the 'and'/'or' certification semantics. The description only restates that filters can be mixed, adding no syntax or format detail beyond the schema, so the 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?

Opens with a specific verb and resource ('Lists NetActuate's data centers (points of presence)') and immediately states the filter dimensions and the no-filter default. It also enumerates the returned fields, so an agent knows exactly what this tool produces versus siblings.

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 concrete example queries ('where does NetActuate have presence', 'anything in Asia') and routes three distinct alternative needs to get_data_center, find_nearest_data_centers and get_compliance_coverage by name. This is explicit when-to-use and when-to-use-something-else guidance.

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