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

Annotations already declare readOnly, idempotent, and non-destructive, so the safety profile is fully covered. The description adds that each row includes 'the subscribers each sent', a modest return-content detail, but nothing about pagination or ordering.

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?

A single compact sentence with no filler, front-loading the resource and its two directions. Slightly awkward phrasing ('with the subscribers each sent') but no waste.

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 simple, optional-parameter read tool with full annotation coverage and complete schema descriptions, the definition gives enough to call it correctly. The absence of an output schema means more return detail would have helped, but the core is present.

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%, documenting both direction and publication_id with defaults and enum values. The description adds no parameter-level meaning beyond the schema, so 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?

The description names the resource (recommendations) and its two directions ('Publications you recommend, or that recommend you'), which is specific enough to distinguish it from recommend_publication, the creation sibling. It lacks an explicit verb like 'list' but the intent is clear.

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 description itself gives no when-to-use guidance or alternatives. Usage hints live in the schema ('check one publication instead', direction default), so the agent must open the schema to learn the two modes.

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