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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety needs no restating. The description adds real value beyond that by surfacing the default filter behavior — an agent that omits filter silently misses completed reminders — and by naming the returned fields.

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?

One purpose sentence followed by two compact examples; nothing is redundant and the default behavior is established before the examples. Every line 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?

An output schema exists, so return values need no prose explanation, and the description still previews the key fields. For a two-parameter, zero-required read tool with full schema coverage, nothing an agent needs to call it correctly is missing.

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 baseline is 3, but the examples go beyond the schema by showing the exact payload shape for each filter mode. The 'target_session' routing parameter is left to the schema, which is acceptable given full coverage.

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 ('List the user's personal Kaption reminders') and immediately enumerates the fields returned (title, time, notification method, completion state). The plural 'list' vs. the sibling 'get_reminder' and the mutating 'manage_reminders' makes the scope separable 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?

The two examples make concrete invocation contexts explicit (default = active only; { filter: "all" } for everything), which directly guides when to use which mode. It stops short of naming alternatives (e.g. use get_reminder for a single reminder), so it is clear context without explicit exclusions.

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