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

Annotations already declare readOnlyHint=true, so safety is covered structurally; the description adds genuine extra context: the required credentials.read scope, the guarantee that secrets are never returned, and the exact per-robot attributes returned. It does not mention pagination or volume limits, which keeps it just short of the top mark.

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, front-loaded with the resource definition, followed by return contents, the secrets caveat, usage routing, and auth requirement. No sentence is filler, and the return-field enumeration is load-bearing because no output schema exists.

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 a zero-parameter read tool with no output schema, the description carries its weight fully: it explains what a robot is, what fields come back, what is deliberately excluded, when to call it, and what permission it needs. Nothing an agent needs to invoke it correctly is missing.

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?

The tool takes no parameters, so schema semantics are irrelevant and the baseline of 4 applies. The description adds a useful note that filtering happens by organisation scope implicitly rather than via inputs, but does not discuss how to narrow results.

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 registry robots) and then defines the resource in plain terms — 'the logins that are not people' — and scopes it to both the Ankra registry and org-run registries. An agent can distinguish this from sibling tools like list_credentials or list_organisation_members without opening a schema.

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 two explicit triggering conditions: call it before update_registry_robot_projects, or call it to answer which login reaches a project. That is a clear when-to-use for both a prerequisite workflow and a direct question, with no inference required.

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