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

No annotations are provided, so the description carries the full behavioral burden, and it discloses almost nothing: not what the comparison returns, not how results are ordered, not how invalid or duplicate ids are handled, and not whether the call is read-only. Only the batch bound of 2–5 is conveyed.

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?

A single front-loaded sentence with zero filler – the scope constraint and the comparison intent come first. Nothing is wasted, though the brevity comes at the cost of the missing details noted elsewhere.

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 annotations, no output schema, and an undocumented parameter, the description needs to do more work than it does. For a comparison tool whose value depends entirely on the shape of the returned side-by-side data, the absence of any return or behavior detail leaves real gaps.

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 only documentation of the single parameter is the description's 'by id'. That usefully identifies the string array as school identifiers, but the 2–5 range restates minItems/maxItems already present in the schema, and nothing is said about formats or ordering.

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 (compare), resource (secondary schools), and scope (2–5, by id), which is enough to tell it apart from the single-record get_school and the query-oriented search_schools. It stops short of explicitly naming those siblings, so it lands at a solid 4 rather than a 5.

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 '2–5 schools by id' framing implies this is the multi-record lookup path once you already have ids, but there is no explicit when-to-use, no mention of when to prefer get_school or search_schools, and no prerequisites stated. Usage is inferable but not guided.

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