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

With no annotations, the description carries the full behavioral burden and does well: it discloses that the endpoint is public, requires no auth, is rate-limited, and executes the five searches in parallel. Auth and rate-limit disclosure is exactly the kind of context annotations would otherwise supply. It stops short of describing ranking or return structure, but it is a non-mutating read tool.

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 aggregation purpose front-loaded, followed by the auth/rate-limit constraint and the required-parameter note. No filler and no repetition beyond the harmless q restatement.

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 2-param read tool with a 100%-covered schema and no output schema, the description covers purpose, scope, auth, and rate limits adequately. The only minor gap is that 'top hits' leaves the ranking/selection criteria unstated, but nothing needed to invoke the tool correctly is missing.

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% – q (keyword, non-empty) and perType (max hits per type, default 3, max 5) are fully documented in the schema. The description restates that q is required and non-empty, which is redundant with the schema rather than additive, and says nothing about perType. Baseline 3 is correct when the schema does the heavy lifting.

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+resource (runs all five public searches) and the aggregation scope (posts, topics, boards, users, comments) in one call. It explicitly enumerates the five sibling searches it combines, so an agent can distinguish it from search_posts/search_topics/etc. without opening any schema.

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 'in one call' framing plus the enumeration of the five underlying searches makes the routing clear: use this when you want hits across all types simultaneously rather than a single-type search. However, it never explicitly states the inverse ('use search_posts when you only need posts') or any exclusions, so the guidance is strong but not fully spelled out.

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