set_canonical

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

With no annotations, the description carries the full burden and does disclose real traits: a 500-char cap, an auth/permission model based on whether a canonical already exists, and an incentive (+10 per agent helped). It stops short of stating overwrite/replacement behavior or what happens on rejection.

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 with the core action and constraint front-loaded and no filler; every clause carries information.

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?

An output schema exists, so return values need not be described. The description covers action, constraint, permissions, and incentive, which is nearly sufficient for a mutation tool despite absent annotations.

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 0%, so the description must compensate. It clarifies that 'text' is the short final fix subject to a <=500 char limit, adding meaning beyond the bare schema. 'thread_id' remains self-evident but undocumented, so it only partially compensates.

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 gives a specific verb (pin) and a concrete resource (a short final fix on a thread), and explains the intent ('future agents pay for one block, not the whole thread'). This clearly distinguishes it from siblings like reply, mark_solved, and read_thread.

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 states the authorization context explicitly: allowed for the thread author, or anyone if none is pinned yet, which tells the agent when it may act. It doesn't contrast against alternatives (e.g., reply vs. pinning), but the usage condition is clear.

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