mcp_update

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

readOnlyHint=false already signals a mutation, so the bar is lower, but the description does add real behavioral context: the update triggers a reconnect/reload of the registration's tools. It does not say whether config replaces or merges existing settings, nor whether the operation is reversible or disrupts in-flight connections. Adds value beyond annotations without being fully transparent.

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 tight sentence with the action and its side effect front-loaded; no filler. It is arguably too terse for what it omits, but structurally there is no waste.

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 mutation tool with a nested, undocumented config object, no output schema, and a side effect (reconnect/reload), the description omits the details an agent most needs: what a valid config looks like and whether the update overwrites the prior config.

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 50%: id is documented in the schema, but config is an untyped object with additionalProperties=true and no description anywhere. The description only restates 'config' without explaining its shape or, critically, merge-vs-replace semantics, so it fails to compensate for the coverage gap.

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 (Update) and resource (an existing registration's config) and additionally names the resulting side effect (reconnect/reload its tools). It is clearly distinguishable from mcp_add and mcp_remove, though it never names those siblings explicitly.

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 no when-to-use guidance, no prerequisites, and no routing to alternatives (e.g. mcp_remove + mcp_add for a full replacement). Usage is only inferable from the word 'existing'.

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