Remove Timeline Marker

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

Annotations already mark this as destructive (destructiveHint: true). The description adds valuable context beyond that: how identical markers are disambiguated ('error if several markers match'), that `all:true` ignores selectors, and the exact return shape `{removed: N}`. It doesn't mention reversibility or side effects, but destructiveHint covers the main risk.

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?

Two sentences carry full operational meaning with zero filler. The primary action and modes are front-loaded, followed by the disambiguation rules and return value. Every clause 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?

For a destructive tool with no output schema, it covers the action, selector rules, error conditions, and return value. A minor gap is that it doesn't explicitly state what happens when no selector or `all` is given, leaving that edge case to the agent's inference. Still, the coverage is strong and sufficient for correct invocation.

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 descriptions are 100% per-property, giving baseline 3. The description goes further by adding the relationship between parameters: exactly one of `index`, `frame`, or `name` for a single target, and `all:true` overriding the selectors. It also clarifies error semantics for ambiguous matches, which is not 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 'Delete one timeline marker, or all of them,' which names a specific verb and resource and explicitly distinguishes the two deletion modes. It is clearly distinct from siblings like create_marker, list_markers, and set_marker, so an agent can select it unambiguously.

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?

Provides clear when-to-use guidance for each parameter path: pass `all:true` to clear everything, or choose exactly one of `index`, `frame`, or `name` for a single target. It also warns that `frame` and `name` error on ambiguity, and points to `list_markers` for getting the `index`, which is practical routing information.

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