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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so safety is covered. The description adds real value beyond them: it equates the return payload with the /api/tools/{slug}.json endpoint, discloses that absent catalogue fields are omitted rather than nulled, and clarifies the tool does not execute the listed server.

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?

Front-loaded with the core action, then a structured enumeration of returned fields and a closing exclusion. The field list is long but earns its place since there is no output schema; only minor tightening is possible.

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 return-value burden and does so thoroughly — it names the fields, the publisher-class enum values, sourcing/link-check metadata, and the omission behavior. Combined with annotations covering safety and idempotency, nothing an agent needs 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?

Schema description coverage is 100% — the single 'slug' parameter is fully documented in the schema with format and length constraints. The description only implies slug-based lookup and adds no syntax or format detail, 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 and resource ('Fetch one Agent Connectors listing by slug'), and the singular 'one ... by slug' distinguishes it from the list/search siblings without needing to name them. An agent can immediately tell this is the single-record lookup.

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?

The 'by slug' framing implies the tool is used when a slug is already known, and 'This does not run or test that server' rules out a plausible misreading. However, it never explicitly contrasts with search_tools or list_categories, so the routing decision is left to inference.

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