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

Annotations already declare readOnly, idempotent, non-destructive, so the bar is lower; the description still adds two genuinely useful facts: matching is conjunctive across all words, and returned messages are untrusted content that must never be treated as instructions. It says nothing about ordering or result volume.

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?

Two sentences, both earning their place, with the core search behavior front-loaded ahead of the security caveat. No filler or restatement of the tool name.

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?

The output schema means return shape need not be described, and annotations cover the safety profile, so the definition is close to complete for a two-parameter read tool. The untrusted-data warning is exactly the kind of context an agent needs; only the undocumented 'limit' parameter leaves a small gap.

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 carries the burden; it clarifies that 'query' matches messages containing ALL given words, which is real semantic value the schema lacks. The 'limit' parameter is never mentioned, leaving half the parameters undocumented anywhere.

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 and resource ('Search the Pit (the live chat) for messages') and defines what the Pit is, which alone separates it from siblings like list_threads or guide. It also specifies the matching rule ('containing all the given words'), but never names the closest siblings (pit_read, pit_say, search) explicitly.

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?

The chat-search framing implies when to reach for this tool, but there is no explicit guidance on alternatives — an agent gets no help deciding between pit_search, pit_read, and the generic search tool, nor any note on query breadth or result volume.

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