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

Annotations already cover the safety profile (readOnlyHint, destructiveHint=false, openWorldHint), so the bar is lower, yet the description adds genuinely useful behavior: it discloses that bank details and National Insurance numbers are never returned, a privacy/response-shape constraint not present in the structured fields. It omits rate limits or pagination behavior, but the sensitive-field exclusion is a meaningful addition.

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 plus an endpoint marker, front-loaded with the returned fields and followed by the sensitive-data exclusion. Every clause 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?

With no output schema, the description carries the burden of describing returns and does so by enumerating the field set and excluding sensitive fields. Combined with fully documented parameters, an agent has enough to call it correctly; only pagination flow detail is left entirely to the schema.

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% — page, filter, and per_page each carry their own descriptions, including enum meanings and the next_page chaining hint. The description adds nothing about parameters, 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?

States a specific verb+resource ('List employees') and enumerates the returned fields (job title, department, division, location, line manager, etc.), so the purpose is unambiguous. It does not explicitly contrast itself with siblings such as breathehr_get_employee or breathehr_list_employee_jobs, so it stops short of full sibling differentiation.

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?

There is no when-to-use guidance: nothing says when to prefer this over breathehr_get_employee for a single record or breathehr_list_employee_jobs for job data. Usage is only implied by the verb 'List', and no prerequisites or exclusions are stated.

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