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

Annotations already cover read-only/idempotent safety, but the description adds non-obvious context: layer=beyond is the paid Attic Beyond tier and requires an API key. It doesn't discuss pagination or result shape, but that is minor for a single read.

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 compact sentences, front-loaded with the core action and followed by precise routing conditions and the auth caveat. Every clause earns its place.

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?

All three required parameters are documented and the tool's output is characterized ('top-5 roster'). With no output schema, the description could say more about return shape, but for a simple list-style read it is essentially sufficient.

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 the schema already documents all three parameters with allowed values. The description reinforces the layer/pillar distinction ('a Headlines / Beyond pillar') but adds no format or syntax detail beyond what the schema provides, so baseline 3 applies.

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 ('Get one weekly top-5 roster') narrowed by the three required dimensions (market, layer, pillar). An agent can distinguish this from attic_get_report_entry and attic_search without reading either 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?

Explicitly routes alternatives: 'For the paragraph on one rank, call attic_get_report_entry. For a name across pillars, use attic_search.' It also lists the trigger phrasings ('top 5', 'who is in the report'), leaving little to inference.

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