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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so safety is covered elsewhere. The description adds nothing beyond those annotations: it doesn't say what the planner computes (50/20/30 split, surplus/deficit), what mode the response takes, or that missing `kind`/`period` changes the output (that behavior is buried in the schema, not the description).

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?

Three words is not concision but under-specification; there is no front-loaded statement of purpose, inputs, or outcome. Nothing is wasted, but nothing is communicated either.

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?

A 2-required-parameter computation tool with no output schema, no annotation elaboration in prose, and undocumented defaults (first version vs. plan response, name-based guessing, annual-to-monthly conversion) demands far more than a three-word label. Everything an agent needs to call it correctly is missing from the description.

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 reported as 0%, so the description was expected to compensate for `income` and `expenses` (with nested name/amount/kind/period) — and it says nothing about any of them. Only the nested `kind` and `period` fields carry any documentation at all, and that lives in the schema, not the description.

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?

"Monthly budget planner" restates the tool name/title rather than describing what the call actually does or returns. It implies a budgeting domain but supplies no verb+resource specificity and does not distinguish it from siblings like planning_event_budget or planning_cost_of_living.

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, when-not-to-use, or alternative-routing guidance at all. An agent cannot tell from the description why it would pick this over planning_event_budget, planning_split_bill, or planning_cost_of_living in the same planning_* family.

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