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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds meaningful extra context beyond them: no external HTTP calls, no auth required, deterministic given unchanged backend state. This is exactly the kind of behavioral detail the schema and annotations don't convey.

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?

Three tight sentences, front-loaded with the return/filter behavior, then side effects, then sibling routing. No redundant or filler content.

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 an output schema covering return values and annotations covering safety, the description adds the scoping, side-effect, and routing details an agent needs. Nothing essential to correct invocation 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 coverage is 100%, so baseline is 3, but the description adds the combined-filter semantics ('content_id, channel, or both; returns all entries when neither') that clarify how the two optional params interact, slightly exceeding what the schema states per-field.

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 ('Return publish state for content pieces') and defines the filtering scope (content_id, channel, or both; all entries otherwise). It clearly separates itself from the mutating siblings it names (post_publish, post_schedule, post_drain).

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 explicit use cases ('inspect what has been published, what is queued, or what errored') and routes the agent to the correct alternative tools for state changes. The when-to-use vs when-to-change distinction is unambiguous.

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