hub_link

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

Annotations already declare readOnlyHint=false, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety and repeat-call profile is covered structurally. The description adds the one-time intent and key provenance, but says nothing about what state the link creates, whether an invalid or already-used key errors, or whether the link can be revoked.

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?

One short sentence with zero filler, and the identity of the input is front-loaded. It is borderline under-specified rather than padded, but nothing in it is wasted.

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, annotation-covered setup tool with no output schema, the description is roughly adequate, but it omits the outcome of a successful link and failure behavior on a bad key, which an agent needs to handle the call correctly.

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% for the single 'key' parameter, and the schema already states 'Exactly as given.' The description's only addition is provenance (a crewchat hook supplies it), which is mildly useful but not syntax or format detail, so the baseline of 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 states a specific verb ('Link') and target ('this session') plus the input source ('the key a crewchat hook gave you'), so an agent knows this is a session-pairing/registration call rather than a messaging or query call like hub_send or hub_inbox. It falls short of 5 because 'link' and 'crewchat hook' are jargon that doesn't pin down the resulting effect.

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?

'once' is a real usage constraint (don't call repeatedly), and the phrase 'the key a crewchat hook gave you' implies a prerequisite step that must happen first. However, no alternative is named and there's no guidance on what to do if no hook key exists or if linking fails, so usage is only implied.

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