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

Annotations already declare destructiveHint=true, idempotentHint=false and readOnlyHint=false, so the safety profile is covered. The description adds only that the mutation lands 'in the manifest' and that an existing entry may be overwritten — useful, but it never says what is lost on overwrite or whether a redeploy/rebuild is required to take effect.

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?

A single short sentence, front-loaded with the action and with zero filler. Its brevity is clean, though it is arguably undersized relative to a five-parameter destructive mutation.

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?

With no output schema, the description need not explain return values, and annotations carry the safety signal. But for a destructive, non-idempotent tool with low parameter documentation, the agent is left without the two things it most needs: what `id` refers to and what an overwrite destroys.

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 only 20% (just the `spec` field is documented), yet the description mentions none of the five parameters. Critically, the required `id` is unexplained — it is unclear whether it identifies the deployment, project, or manifest — and `dev` and `manager` get no elaboration.

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 names a concrete verb pair and resource: 'Add or update a package in the manifest.' An agent can tell this is the write counterpart to packages_list/packages_remove, though no sibling is named explicitly and the add-vs-update (upsert) ambiguity is not resolved.

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?

There is no when-to-use guidance, no prerequisites, and no mention of when not to use it (e.g., to change a version already present, or when packages_remove is the right call). The agent must infer call conditions entirely from the tool name.

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