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

Annotations already declare readOnly=false, destructive=false and idempotent=true, so the safety profile is covered structurally. The description adds the non-obvious behavioral trait that unspecified fields are left untouched, which is exactly the kind of context annotations cannot convey. It stops short of stating auth requirements or what the response contains.

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 short sentences, each carrying distinct information: what can change, how to send it, and where ids come from. The field enumeration is front-loaded and nothing is redundant.

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 5-parameter partial-update tool with annotations covering safety and an explicit id prerequisite, the description covers all the axes an agent needs to invoke it correctly. Only a note about the response shape is absent, which is minor given there is no output schema.

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 80%, so the schema already documents place ("1 is the top"), sphere (empty string removes it) and point_id provenance. The description restates the same ordering and id-source facts rather than adding new semantics such as what happens when place exceeds the list length or whether sphere accepts partial-name matches. 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 names a specific verb and resource and then enumerates every mutable facet: rename, star/unstar, move sphere, reorder place. That enumeration lets an agent separate it from add_focus_point, delete_focus_point, update_sphere and the other siblings without opening any schema.

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" clearly establishes this as a partial/patch operation, and "Point ids come from list_focus" tells the agent the prerequisite step before calling. There is no explicit when-not guidance (e.g. use delete_focus_point to remove), but the usage context is unambiguous.

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