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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the bar is lower, and the description adds real value by disclosing patch semantics (omitted fields are left untouched rather than cleared) and clarifying that completion is expressed through completed_at. It stops short of saying what happens to progress values once a goal is marked done, or whether updates are reversible.

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, zero filler, with the mutation scope front-loaded and the usage constraint ("send only what changes") placed last as a rule. Nothing could be cut without losing meaning.

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 mutation tool with annotations, a required goalId, and no output schema is adequately covered: the agent knows it is a partial update, which fields it can change, and how completion is expressed. The unmentioned title parameter is the only remaining gap.

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 67%, and the description partially compensates by naming target_value, the date fields, manual_progress, and the meaning of completed_at. Critically, the title parameter is never mentioned in the description and has no schema description, leaving one parameter wholly undocumented.

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 (changes/updates) and resource (a goal), and enumerates the mutable facets: target, dates, progress, and completion. An agent can distinguish it from create_goal and list_student_goals, but the description 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?

"Send only what changes" implies patch-style usage and rules out full-object replacement, which is useful. However, there is no explicit statement of when to prefer this over create_goal, no prerequisite (e.g., goalId must come from list_student_goals), and no guidance on error or not-found conditions.

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