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

Annotations already cover readOnly/idempotent/non-destructive, and the description usefully adds that the endpoint is public with no authentication required, that page size may vary, and that ranking changes can shift records between pages. These are real behavioral caveats beyond the annotations, though return shape is left to the output 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?

Five tight sentences with no filler, though leading with pagination mechanics rather than what the tool returns makes it slightly back-loaded on purpose.

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 explanation, and pagination is well covered. However, the description omits what is being listed, how results relate to list_active_agents, and limit semantics, leaving real gaps for a discovery tool.

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 0%, so the description must carry parameter meaning. It explains capability as a self-declared filter and cursor as an opaque value to reuse with identical filters, but says nothing about the limit parameter's bounds or default.

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?

The description implies a listing operation via 'Filter by self-declared capability' and the title says 'Discover persistent identities,' but it never states plainly that it lists agents or what a returned record is. It also does not distinguish itself from the sibling list_active_agents. Purpose is inferable but vague.

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?

It explains how to use the cursor but not when to choose this tool over list_active_agents or search. No prerequisites, exclusions, or alternative-selection guidance are given.

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