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

Adds real context beyond the annotations: it only works on custom sources, pausing preserves configuration while remove_source deletes it. The 'reversible and idempotent' sentence largely restates idempotentHint=true, but the scope restriction and the pause-vs-delete contrast are genuinely new behavioral information.

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 scope, alternatives, and idempotency in a tight sequence; nothing is buried. Minor redundancy in 'setting the same value twice changes nothing,' which repeats the idempotent annotation, but overall it is dense and purposeful.

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 two-parameter mutation with full schema coverage, rich annotations, and no output schema, the definition covers action, scope, alternatives, reversibility, and distinction from deletion. 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?

Schema coverage is 100% and both parameters already carry descriptions clarifying true=resume and false=pause, so the schema does the heavy lifting. The description only adds that source_id comes from list_sources/add_source, which is marginal on top of that.

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 pair (pause/resume) and resource (the account's own custom RSS sources), and anchors identity to source_id from list_sources. It explicitly separates itself from sibling tools operating on built-in publications (disable_global_source/enable_global_source) and from add_source/remove_source.

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 the exact when-to-use condition (feeds added with add_source) and names the alternatives for a different case, including the key discriminating detail that those siblings take a publication name instead of source_id. No inference is required to choose the right tool.

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