update_marker

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

No annotations are provided, so the description carries the full behavioral disclosure burden. It discloses that the operation mutates an existing marker and that the sequence is not required to be active, but it does not describe failure behavior, overwrite semantics, or what happens when the markerId does not exist. The extra non-active-sequence note is useful, but more behavioral context would be valuable.

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 definition is two short, focused sentences. The first sentence states the core operation, and the second adds a useful constraint without padding. There is no filler and no redundant restatement of schema content.

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?

Together with the fully documented schema, the description gives an agent enough to understand what the tool does, what parameters matter, and that it targets a non-active sequence. The missing return/error details are a minor gap because the agent can construct a correct invocation without them.

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%, and every parameter has a meaningful description, including the color value forms and defaults. The description adds the phrase "the specified sequence," which aligns with sequenceId, but does not add significant parameter semantics beyond what the schema already documents. 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?

The description states a specific verb and resource: "Updates an existing marker's properties in the specified sequence." This clearly distinguishes the tool from sibling marker tools such as add_marker, delete_marker, and list_markers. The added sentence about the sequence not needing to be the active one further differentiates it from tools that only act on the active sequence.

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 gives clear usage context: use this tool to modify an existing marker, and the target sequence can be any sequence, not necessarily the active one. It does not explicitly name alternatives such as add_marker or delete_marker, but the update-vs-create-vs-delete usage is obvious from the phrasing, so the agent can select it correctly.

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