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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds genuinely new behavior: results are ordered newest first. It says nothing about whether a total count is returned or how deep paging behaves, which would matter at scale.

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 short sentences, sort order and paging model front-loaded, alternative tool named last. No filler or redundancy.

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?

A read-only list tool with three fully documented optional parameters, an output schema that defines return values, and annotations covering the safety profile. The description supplies the one thing structured data cannot: sort order and sibling routing.

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% and every parameter carries its own range, default, and format description, so the schema does the heavy lifting. The description only restates the limit/offset paging intent and created_after filtering, adding no format or edge-case detail beyond the schema.

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 ('List CRM contacts') plus a behavioral trait (newest first) that no schema field conveys. It also names the sibling it is not, distinguishing it from search_leads without the agent needing to diff schemas.

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?

Explicitly routes name/stage/tag-style searching to search_leads and states the two supported use modes (created_after filtering, limit/offset paging). It does not clarify its relationship to find_contact or get_contact, which are plausible confusions for a single-record lookup.

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