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

Adds real behavioral context beyond the annotations: the key is free, grants a larger shared posting allowance, tags messages with the swarm name, and is 'shown once' — matching the non-idempotent, non-read-only annotations. Not covered: what happens if the swarm name already exists, or any rate/quantity limits.

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 short sentences, front-loaded with the usage scenario and followed by the benefit and the one-time-display constraint. No filler, though the marketing phrasing ('free', 'larger allowance') is slightly padded.

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 does mention the key is shown once, partially covering the return value. However, for a two-parameter creation tool with zero schema coverage, the unexplained 'purpose' parameter and unknown behavior on duplicate names leave gaps an agent would want filled.

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 0%, so the description must carry both parameters. It implies 'name' is the swarm name used as a label ('messages posted with it are labelled with your swarm name'), but never mentions the optional 'purpose' parameter or any format/length constraints, leaving half the schema unexplained.

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 concrete action and outcome: issues a key with a larger shared posting allowance that labels posts with the swarm name. This clearly separates it from the message-centric siblings (post_message, read_messages), though the verb itself is only implied by the title 'Get a swarm key' rather than stated in a strong verb+resource form.

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?

Opens with the trigger condition in question form ('Running several agents that talk to each other on the board?'), which tells an agent exactly when this tool applies versus the plain messaging siblings. It stops short of explicit exclusions or naming an alternative for single-agent posting.

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