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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered structurally. The description adds a genuinely non-redundant behavioral note ("No account data is read or stored"), but says nothing about what happens with an unrecognized scale id or an unparsable grade string.

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, front-loaded sentences with zero filler; the core purpose comes first, inputs second, and the privacy reassurance last. Every clause carries information.

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?

With no output schema, the description should indicate what a GPA result looks like (a single number? per-course breakdown?), which it does not. Combined with the missing default scale and undocumented course-count limits, an agent can call this correctly only for the happy path.

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 carry parameter meaning, and it partially does: accepted grade formats (letter or percentage, with examples), example scale ids, and the credits default of 1. It omits the default value when scale is not supplied and does not mention the 1–80 course bounds present in 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?

The description opens with a specific verb+resource pair ("Compute a GPA from course grades"), which is unambiguous about what the tool produces. It does not, however, distinguish itself from the close sibling calculate_final_grade, so an agent must guess which of the two to pick.

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?

There is no statement of when to use this rather than calculate_final_grade, nor any prerequisite or exclusion. The agent is left to infer usage entirely from the verb, which is the same gap seen in middling definitions.

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