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

With no annotations provided, the description carries the burden and mostly does: it discloses that results are account-scoped and permission-filtered, that absence means the tool is disabled rather than nonexistent, and that responses are 200/JSON. It does not state read-only/no-side-effects explicitly or whether the list is cached, so one behavioral trait is left implicit.

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?

The core content is front-loaded and tight: purpose, trigger, constraint, and return anatomy in three short sentences. The trailing '### Responses: 200 ... Content-Type: application/json' block is boilerplate from the spec dump and earns no place in the description.

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?

There is no output schema, no annotations, and no parameters, yet the description still explains the two return fields (capabilities and tools), the filtering semantics, and how to use each field. Nothing an agent needs to call this correctly and interpret it 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 zero parameters, so the baseline is 4; there is nothing for the description to disambiguate. It correctly adds no parameter noise.

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 Tools') and immediately narrows the scope: the Iridium tools available to this account, filtered by what the user has enabled. It is unmistakably a discovery/meta tool, which cleanly separates it from all 60+ action siblings like run_outreach_pipeline or list_drafts.

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 an explicit trigger ('answering "what can you do?" without guessing') and an explicit negative rule with a consequence: 'A tool absent from this list is switched off for this account, so do not offer it.' It also tells the agent which return field to use for which task (capabilities for user-facing answers, tools for picking the call).

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