MarathonAddMarathonNewStudents

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

The description goes beyond the annotations by explicitly warning that although this is a GET, it mutates state by inviting students, and that client-side approval is required. This is valuable behavioral context for an agent.

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 short and front-loaded, but redundant: 'Note: this is a GET that mutates state' and 'WARNING: Mutates state' essentially repeat the same warning. The redundancy costs it a higher score.

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?

The essential mutation and approval caveats are present, and the main purpose is clear. However, the ModeratorsIds parameter is unexplained, and there is no indication of what the response or side effects look like beyond inviting students. Adequate but with gaps.

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 100%, but the parameter descriptions are generic ('array (optional)', 'integer (optional)'). The description adds that the operation is 'by email', hinting at Emails, but does not explain MarathonId, ModeratorsIds, or MailMessageLanguageId beyond what the schema already provides.

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 clearly states the specific action: adding new students to a marathon by email. It is distinguishable from sibling tools that manage moderators, activation, or student retrieval.

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?

The description makes the use case clear: invite new students to a marathon by email, with client-side approval required. It does not explicitly name alternatives or exclusions, but the context is unambiguous.

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