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

Annotations already declare readOnlyHint=true, so safety is covered; the description adds genuinely useful behavior beyond that, disclosing the monthly rescan-and-compare cadence and enumerating what each returned record contains (status, plan coverage, next check date, latest metrics, changes/digest). It stops short of mentioning pagination behavior or input constraints.

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?

Front-loaded with the core action and definition, then a dense but purposeful inventory of returned fields. Slightly heavy in the middle clause listing every metric, but no sentence is filler given the absence of an output schema.

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 and only one parameter, the description fully carries the burden of describing the return payload, including change data as both structured `changes` and `digest` text plus a count of followed niches. An agent has everything needed to call and interpret this tool.

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 100% and the single `limit` parameter is fully documented in the schema (range 1-50, default 20). The description adds nothing about the parameter, which is acceptable given the schema does the work, so the baseline 3 applies.

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 and resource ('Lists the niches the account follows') and immediately resolves the domain ambiguity by defining a project as a followed niche that is rescanned monthly. This cleanly separates it from siblings like list_research, get_project, and follow_niche without needing to name them.

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?

Usage is only implied: an agent can infer this is the enumeration tool for followed niches, but there is no explicit when-to-use guidance, no exclusions, and no routing to alternatives such as get_project for a single niche or list_research for research artifacts.

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