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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile needs no restating. The description adds value by disclosing the compared facets, but says nothing about behavior on unknown or duplicate slugs, or about how the servers are ordered in the result.

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 front-loaded sentence with the action, the input key ('by slug'), and the compared dimensions, with zero filler. The cardinality bound is placed early where it has the most operational value.

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 and annotations cover the safety profile, so return values need not be described. What remains is the cardinality inconsistency (description says two to five, schema permits one) and unaddressed error behavior for bad slugs, which keeps it from a 5.

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%, so both parameters are already documented and the baseline applies. The description adds the 'by slug' framing and a 2-to-5 cardinality hint, but that hint conflicts with the schema's minItems=1, which could mislead an agent about whether a single slug is legal.

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 ('Compare ... servers side by side by slug') and enumerates exactly what is compared: trust signals, auth, hosting, transport, tools count, license. That makes the output shape predictable and distinguishes it from single-server siblings like get_server. It stops short of naming a sibling explicitly, so 4 rather than 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 phrase 'side by side' plus 'two to five servers' implies the multi-server comparison scenario, which implicitly routes the agent away from get_server. However there is no explicit when-to-use/when-not statement and no mention of the alternative tools (get_server, search_servers, recommend_servers) for single-lookup or discovery cases.

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