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

With no annotations, the description carries the full burden and does well: it reveals the percentile-rank semantics, the direction convention ('for efficiency_ratio lower is better'), the unit system (fractions on YTD flows, annualized over average assets, re-basing each January), and the meaning of each peer_basis band. It omits any statement about permissions, rate limits, or behavior on an invalid cert/quarter, which keeps it short of a 5.

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?

Information-dense and front-loaded: the return profile comes first, then identity, then peer_basis semantics, then units, then the sibling routing. It is a single heavy block, but each sentence carries distinct content and little is redundant.

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?

For a three-parameter read tool with no annotations and no output schema, the description covers the returned fields, the ranking convention, the unit interpretation, and the alternative tool. It does not cover failure modes or access requirements, but the essentials for a correct invocation are present.

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 fully compensates: cert is defined as the FDIC certificate number with a lookup tool suggested, quarter is described as defaulting to latest, and peer_basis is enumerated with its three values and the full definition of the five asset bands. Every parameter gains meaning that the bare schema does not provide.

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 concrete verb+resource+scope ('One bank against its peers in a quarter') and enumerates the exact outputs (value, peer median, quartiles, percentile rank) and the four metrics covered. It also distinguishes itself from sibling peer_compare by routing credit unions there, so an agent can tell it apart without opening the 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 names the alternative tool for a whole class of entity ('For credit unions use peer_compare') and gives the prerequisite path for the required identifier ('find_bank looks it up by name'). The default behaviors (quarter = latest, peer_basis = size_band) further tell the agent when it can omit parameters.

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