assert_contains

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

With no annotations, the description carries the full behavioral burden. It usefully discloses failure behavior ('on failure includes a screen excerpt'), which is the key trait of an assertion tool, but says nothing about success behavior, whether it blocks/waits/polls, timeouts, or how failure is signalled to the agent (error vs. status flag).

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 tight sentence with the assertion condition front-loaded and the failure side-effect appended. No filler or redundancy.

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?

An output schema exists, so return-value documentation is not required. For a simple assertion tool that is adequate, but the two undocumented optional parameters and the absence of any annotation coverage or session/buffer semantics leave gaps an agent must guess at.

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 0% across three parameters. The description clarifies only `text` (the required match string); `session_id` (which session's screen is asserted) and `use_buffer` (an undocumented anyOf/null flag) get no explanation in either schema or description, leaving real ambiguity for a multi-session tool.

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: assert that the current screen contains `text`. It is clearly distinguished from positional siblings like assert_at_position and get_screen_region, but it does not differentiate itself from the similar-sounding expect_text, which an agent would also consider for this task.

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?

The description gives no when-to-use or when-not-to-use guidance, and never mentions the close alternative expect_text or any prerequisites (e.g. that a TUI session must be launched and active first). Usage is only inferable from the word 'assert'.

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