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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds context beyond that: the underlying endpoint (GET /api/v6.1/users), the identity field to reuse downstream, and the 'valid' flag semantics for active vs inactive users.

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 short, front-loaded sentences with no filler; the core purpose and the downstream usage hint come before the filter list. Slightly dense parenthetical stacking, but nothing is wasted.

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 naming the returned fields (id, name, department, email, phone). Filters, cross-tool usage, and endpoint are all covered; only pagination behavior is omitted, and the schema already documents next_offset handling.

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 100%, so the baseline would be 3, but the description adds real information the open-ended 'filters' object cannot convey: the actual filterable field names (user_id, contact_name, email, contact_mobile, valid) and the meaning of valid=1. Pagination params are left to the schema, which documents them well.

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 and resource ('List the Getfly CRM users (employees)') and enumerates the returned fields, so the agent knows exactly what it gets. It is clearly distinguishable from the singular sibling getfly_get_user and from unrelated list tools like getfly_list_accounts.

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?

Adds genuine routing guidance the schema cannot: 'Use the user_name (login name) for the recipient/manager arguments of the create tools,' linking this lookup to the create_* siblings. It also names concrete filter use cases (e.g. valid=1 for active users), though it never explicitly contrasts itself with getfly_get_user.

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