blocker.list

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

The readOnlyHint annotation already covers safety, but the description adds useful behavioral context: results are scoped to the current session and returned as a JSON array with named fields. It does not discuss pagination or ordering, but for a simple read-only list that is a minor omission.

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 description is front-loaded with the core action and scope, then adds output fields and usage guidance in compact sentences. Every sentence contributes either scope, return format, or actionable usage context.

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 one-parameter, read-only list tool without an output schema, the description supplies the missing return-field information and sufficient usage guidance. An agent has enough context to call it correctly and understand when to prefer open_only=true.

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 the boolean is already defined in structured data. The description adds value beyond the schema by explaining practical reasons to set open_only=true, especially for duplicate avoidance and ID lookup before blocker.resolve.

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 uses a specific verb and resource: 'List the current session's blockers'. It also names the return shape and fields, and distinguishes this tool from blocker.create and blocker.resolve by explaining its role in those workflows.

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?

It gives explicit usage guidance for open_only=true: see what still blocks work, avoid duplicates before blocker.create, and find the ID needed by blocker.resolve. This names concrete alternatives and conditions rather than leaving usage to inference.

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