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

Annotations already establish the safety profile (readOnlyHint=true, destructiveHint=false), so the bar is lower. The description adds real value beyond that by disclosing the workflow chaining (event IDs feed register/get, shift IDs feed sign_up) and the 'active school' scope. It stops short of any auth or rate-limit context, but the workflow disclosure is substantive.

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?

Front-loaded with what the tool returns, then workflow routing. Every sentence is informative, though 'Optionally filter by date range' is mildly redundant given the schema already documents this, adding slight bulk.

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?

An output schema exists, so return values need no further explanation. The description supplies the scope ('active school'), the ID-chaining workflow, and the disambiguation against registration/cancellation siblings, leaving nothing an agent needs to call it correctly.

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%, so both date parameters (start_date, end_date, with format and inclusivity) are fully documented in the schema. The description only restates 'Optionally filter by date range' without adding syntax or semantics, so baseline 3 is appropriate.

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 ('Returns upcoming events for the user's active school') and enumerates the returned fields (date, times, location, registration-closed flag). An agent can distinguish it from siblings like get_school_event or list_school_programs without opening any 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?

Explicit routing: event IDs feed register_for_event and get_school_event; get_school_event is required to reach volunteer shifts; and registration/signup review is directed to list_my_event_registrations / list_my_volunteer_signups alternatives. Names both when to use this tool and where to go instead.

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