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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds meaningful behavioral context: it is deterministic and performs metadata checks, and it restricts input to public Agent Cards. This goes beyond the annotation baseline and clarifies what the tool actually does.

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?

The description is a single, front-loaded sentence with no filler. Every word contributes to the purpose. It is efficiently written and easy to parse.

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?

There is no output schema, yet the description does not explain what the ranking output looks like, what 'deterministic task-specific metadata checks' refer to, or how task_class affects behavior. An agent would need additional inference to use the tool correctly and interpret its results.

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 must compensate. It only hints that 'candidates' are supplied public Agent Cards, but it does not explain the structure of the candidate objects or the role of the optional task_class parameter. Most parameter meaning is left undocumented.

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?

The description states a specific action ('Rank'), a resource ('supplied public Agent Cards'), and a method ('deterministic task-specific metadata checks'). It clearly distinguishes from siblings like assess_agent_card by focusing on ranking multiple candidates rather than assessing a single one.

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?

Usage is implied: the verb 'Rank' and mention of multiple cards suggest it is for comparing a set of candidates. However, there is no explicit guidance about when to use this tool versus assess_agent_card or the other siblings, and no exclusions or conditions are stated.

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